I am currently using jquery mobile datebox (http://dev.jtsage.com/jQM-DateBox/) to display a calendar. I stuck the input in a div with display: none, and then I manually activat
Please try
<div style="visibility:hidden; height: 0px;">
<label for="mydate">Some Date</label>
<input name="mydate" id="mydate" type="date" data-role="datebox"
data-options='{"mode": "calbox"}'>
</div>
jQM-DateBox calculates its position probably from it's parent and because it isn't rendered (because of the display:none) this will be 0,0, setting visibility will fix this